It is possible to find a rare silver dollar coin if you know where to look. Such coins as the early US Morgan Silver dollar are available at auctions and dealers for a reasonable price.
The first silver dollars were minted around 1794 and according to Wikipedia, The U.S. Mint produced silver dollar coins from 1794 to 1803, then stopped regular production of silver dollars until 1836. Original silver dollars from this period are highly prized by coin collectors and are exceptionally valuable, especially the 1804 silver dollar, which is one of the rarest and most famous coins in the world.
The Mint ceased production of silver dollars in 1803, and the 1804 silver dollar was not actually minted until 1834, when the U.S. Department of State decided that a few coins with the unusual date of 1804 might make excellent gifts to rulers in Asia in exchange for trade advantages. Only 15 silver dollars with the date of 1804 are known to exist; in 1999, one of them sold at auction for more than $4 million. So if you came across one you would be entitled to jump up and down with joy.
It is a good idea when purchasing at an auction to ensure the seller is genuine. On eBay this can be done by checking the feedback and if they are a power seller. A power seller with a 99% or more score is considered a long term buyer and reliable enough to buy from them. Most experienced eBay buyers either dib a large enough amount up front to discourage other bidders or bid at the past minute to 'pip at the post' as it were other bidders in order to capture the item.
Buying from dealers also requires some due diligence and common sense.
Ensure that the dealer is a reputable dealer and has contact details such as snail mail address and phone numbers. Ask how long they have been around. Do they have a returns policy. Check out the terms and conditions of sale. Many people do not because it is a boring read, but this can cost them later.
Do they have such icons on their site as the Better Business Bureau on line (BBB), TRUSTe and a secure connection for credit card transactions for example.
All these are important points to keep in mind, especially when you are paying big dollars for rare coins.
It is fun seeking out and collecting a rare silver dollar coin provided you keep the above points in mind.